Trying to run them over is not the best move. Same goes for stopping the car and getting out. For all you know, they may be undercover cops in the process of making an arrest, and that interference could get one or more of them killed. Pull over, make the call, and if the situation allows it, double back and observe. At the very least, you can try to act as a witness to what occurs, and report what you see to the operator.

Call law enforcement. Point the car at the thugs (assuming there's room for it). Put headlights on high beam and honk your horn for an extended duration. Proceed to option 1 or something else, depending on the reaction of the thugs.

Trying to run them over is not the best move. Same goes for stopping the car and getting out. For all you know, they may be undercover cops in the process of making an arrest, and that interference could get one or more of them killed. Pull over, make the call, and if the situation allows it, double back and observe. At the very least, you can try to act as a witness to what occurs, and report what you see to the operator.

Right answer, right reasoning, this is exactly what one ought to do in such a situation.